This competing renewal application requests funding for Years 11-15 to continue study of the onset, course, causes, and consequences of alcohol use and alcohol use disorders in The Pittsburgh ADHD Longitudinal Study (PALS). In the PALS, 364 children with ADHD (probands) were ascertained in their elementary school-aged years following their participation in the ADHD Summer Treatment Program at WPIC, University of Pittsburgh. This is the largest study of its kind: rigorously diagnosed ADHD in childhood, detailed comprehensive childhood data (including standardized and objective data), and detailed annual follow-up assessments of domains theoretically related to the development of alcohol abuse and alcohol dependence (e.g., family history of alcoholism; alcohol expectancies). A nonADHD demographically similar group of participants (n=240) was recruited during the first follow-up of the probands between grant years 1 and 5 when participant ages ranged from 11 to 25. Using a cohort sequential design, all participants have been followed annually since recruitment into the PALS; retention is over 90% and a multiple reporter approach has been adopted throughout. A sampling of findings includes: 1) a higher risk for heavy drinking and AUD in proband adolescents; 2) absence of proband-control differences for AUD at 18-25 yrs when controls are also drinking heavily; 3) positive association between duration of lifetime stimulant treatment and early adulthood binge drinking, 4) weak associations between childhood conduct problems and later drinking outcomes but strong concurrent associations, supporting an ADHD?conduct?AUD pathway, and 5) moderating influence of parental monitoring on ADHD risk for longitudinal growth in adolescent drinking frequency. Continued follow-up (annual to age 25, age-targeted periodic assessments thereafter) is requested to determine whether early heavy drinking patterns persist through the twenties when desistance is the U.S. norm, to determine whether new cases of AUD develop in the mid-to-late 20s, and to study the putative causal mechanisms underlying these AUD developments and consequences in early adulthood.